1. Field of the Invention
The present invention relates to a retention device, and particularly to a retention device for retaining a combination of a daughter card and a heat sink mounted on the daughter card to an electrical connector.
2. Description of the Prior Art
Taiwan Patent Application Nos. 86207711, 86207803 and 86211054 each discloses a retention device. Referring to FIG. 1, a conventional retention device 8 comprises a base 80 and a pair of vertical frames 81 positioned at opposite ends of the base 80. Each vertical frame 81 defines an opening 83 in distal end of a central board 82 thereof. Correspondingly, a daughter card 84 forms a pair of projections 85 on opposite side edges thereof. In assembly, the vertical frames 81 are outwardly expanded so that the daughter card 84 can be downwardly accommodated therebetween. The projections 85 are received in corresponding openings 83 thereby preventing a disengagement of the daughter card 84 from the retention device 8.
Referring to FIG. 2, a second conventional retention device 9 comprises a base 90, a pair of vertical frames 93 disposed at opposite ends of the base 90, and a pair of locking members 91 each being mounted to a corresponding vertical frame 93. Each vertical frame 93 defines an opening 96. Each locking member 91 forms a spring arm 94, forming a projection 95 thereon, in one lateral face thereof and defines a groove 97 in an opposite lateral face thereof. In operation, a daughter card 92 and a heat sink 98 mounted on the daughter card 92 are downwardly assembled in the retention device 9 with opposite side edges thereof retained in the vertical frames 93. The locking members 91 are then downwardly assembled to corresponding vertical frames 93 with the projections 95 thereof received in corresponding openings 96 and the grooves 97 accommodating top edges (not labeled) of the daughter card 92, thereby retaining the daughter card 92 and the heat sink 98 in the retention device 9.
However, one or more disadvantages may exist in the above conventional retention devices. First, the vertical frames 81, 93 are very stiff and the force needed to expand them outward is very large. Second, the retention devices 8, 9 do not have a card ejector, so ejection of the daughter cards 84, 92 from corresponding electrical connectors (not shown) may be difficult. Hence, an improved retention device is required to overcome the disadvantages of the prior art.